Strongly regular graphs arising from Hermitian varieties

For the Hermitian variety H-r = H(r,q2) of PG(r, q(2)) we show that the associated linear representation graph Gamma(*)(R)(H) is isomorphic to an affine polar graph and we use this isomorphism to determine the full automorphism group of 1.7.(9-1). We provide a classification of maximal cliques of Gamma(*)(r)(H) in geometric terms showing that their length is equal to qr for r even and qr+1 for r odd. We also show that maximal cliques of Gamma(*)(r) (H) are not equivalent under the action of Aut(r:.(91)) and they fall into 1/2r + 1 and + 3) classes according as r is even or odd.